Calgary Jeep Association

4x4 Related Groups => Tech Talk => Topic started by: specialk on October 19, 2009, 07:46:33 PM

Title: Low speed vibration in TJ front end.
Post by: specialk on October 19, 2009, 07:46:33 PM

I've got a new vibration happening in the front end of my TJ.  It started on Sunday on the way home from wheeling.  Noticed it as I was slowing down to a stop.  Had trouble making it happen again on the way home. Seemed to come and go.  Stopped at the car wash and it sounded/felt real bad when I drove out.  Seemed to go away on the way home (4-5 minute drive). Drove to work with no problem. Driving home in the rain tonight really brought it back bad.  It is very noticable at slow speeds - under 15 kms.   It sounds like a load ticking, changing speed with tire speed.  I can feel it in the steering and shifter and floor.  Can't tell at faster speed but it does not seem to be there.

Any thoughts?

Title: Re: Low speed vibration in TJ front end.
Post by: The Machinist on October 19, 2009, 07:58:41 PM

Sounds like it may be a front driveshaft u-joint.  Does the ticking sound like it's per revolution of the tire or per revolution of the front driveshaft?

Title: Re: Low speed vibration in TJ front end.
Post by: specialk on October 19, 2009, 08:07:10 PM

Hmmm.  I'm going to say drive shaft rotation.  I did grab it and give it a shake when parked but didn't feel anything move.

How would I go about testing this to confirm it is the drive shaft?  Am I still safe to drive or should I park it?

Title: Re: Low speed vibration in TJ front end.
Post by: The Machinist on October 19, 2009, 08:13:41 PM

Dis-connect the front driveshaft at the axle and check the u-joint for play, there shouldn't be any.  You can pull out the drive shaft and take it for a spin to confirm.  I've checked my driveshafts without pulling them before, they felt tight while installed but once I pulled it out I noticed the u-joint was toast.  You can drive a 2wd jeep until you fix the u-joint.

Title: Re: Low speed vibration in TJ front end.
Post by: specialk on October 19, 2009, 08:20:35 PM

Thanks Jamie!   ;D  My first u-joint!!!

Last question.  I'm sure there are all kinds of u joints out there.  Are some better than others? Where would you suggest I get one if it is toast?

Title: Re: Low speed vibration in TJ front end.
Post by: The Machinist on October 19, 2009, 08:32:10 PM

I like spicer u-joints, DSI has them.  I'll usually replace the straps and bolts when I do them also.  You can also get u-joints at part source, auto value, etc..  Greasables are better, as long as you remember to grease them.

Title: Re: Low speed vibration in TJ front end.
Post by: specialk on October 19, 2009, 08:53:58 PM

Thanks man!!!

Title: Re: Low speed vibration in TJ front end.
Post by: JackstandJohnny on October 19, 2009, 09:00:15 PM

kevin, pull the driveshaft first though. take it for a rip....... those are also symptoms of bad unit bearings........

Title: Re: Low speed vibration in TJ front end.
Post by: specialk on October 19, 2009, 09:02:51 PM

Will do. 

Title: Re: Low speed vibration in TJ front end.
Post by: specialk on October 20, 2009, 06:29:19 PM

Crud...  bad unit bearings.  Jamey and I are going to perform the surgery on Thursday...  :-\

Title: Re: Low speed vibration in TJ front end.
Post by: SwampSinger on October 20, 2009, 08:38:44 PM

I usually listen to the speed of the skeek... if it goes at the speed of the wheel or the driveshaft ... it it's the shaft, it will be real fast skeek and the wheel is slower.

You guys have fun  ;D... if Jamie for some reason can't help you I'll give you a hand

Title: Re: Low speed vibration in TJ front end.
Post by: specialk on October 23, 2009, 11:30:08 AM

Unit bearings are back in - BIG thanks to Jamey and Noel for walking me through the steps.  Should be easy-peasy next time.  BUT... we also found the rear u-joint on the front drive shaft was seizing.  That was causing the vibration.  So off to the shop with that next week. 
 
Prairie Creek bad...  ;)

Title: Re: Low speed vibration in TJ front end.
Post by: The Machinist on October 23, 2009, 03:15:53 PM

Quote from: specialk on October 23, 2009, 11:30:08 AM

Unit bearings are back in - BIG thanks to Jamey and Noel for walking me through the steps.  Should be easy-peasy next time.  BUT... we also found the rear u-joint on the front drive shaft was seizing.  That was causing the vibration.  So off to the shop with that next week. 
 
Prairie Creek bad...  ;)

No problem, it's all ways good times turning wrenches on someone else's jeep!   :)